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THE POPULAR SCIENCE MONTHLY. 



were now revolved the result would be a plain circle cut into the 

 steel plate ; or, if the oval slide which is built into the chuck is 

 in operation, the result would be an oval (Fig. 12). 



The several cams, when in use, cause the " beds " (of which 

 there are two, laid on rollers) to move back and forth, or to the 

 right and left, as the operator may desire, once for each revolu- 

 tion. Now, suppose one cam was geared to revolve eight times 

 while the chuck is revolving once, we would then have eight 



Fig. 11. Geometrical Lathe. From ' Paper and Press," by the kiudiie.ss of W. M. I'atton. 



vibrations of the " bed," or eight waves in the line which was 

 before a plain circle ; therefore, we would now have an eight-sided 

 figure, or a circle with eight bulges in it, (See inside line of the 

 figure below.) If we now put another cam in motion, geared to 

 revolve twenty-four times to the chuck once and the first cam's 

 eight times, we would have twenty-four waves upon eight waves 

 upon a circle, giving a line like that of the outside in the same 

 figure (Fig. 13). 



This has given us one of the many beautiful and perfectly 

 geometrical forms that this wonderful and almost human machine 

 is capable of producing under the management of a skilled artist. 



